The invention relates to machine-assisted respiration of a patient.
Machine-assisted respiration of a patient, or subject, is known in the art. Common examples may include positive airway pressure devices, e.g. continuous or bi-level positive airway pressure (CPAP/BiPAP), and/or other devices. A respiratory device may assist a subject to breath in, breath out, or both. A subject may experience discomfort when a respiratory device initiates an inspiration or expiration that fails to coincide with the subject's natural breathing rhythm. Improved comfort may aid improved therapeutic compliance regarding the use of a respiratory device.
The disclosure relates to a method for controlling respiratory assistance of a subject, the subject having an airway. In one embodiment, the method comprises generating a pressurized flow of breathable gas for delivery to the airway of a subject at an inspiratory pressure level during a breath by the subject, wherein the breath has inspiratory volume during an inspiratory phase and expiratory volume during an expiratory phase; determining a breathing rate of the subject; adjusting a first volume threshold based on the determined breathing rate; monitoring the inspiratory volume of the breath by the subject; comparing the inspiratory volume to the first volume threshold to determine when the inspiratory volume of the breath breaches the first volume threshold; and responsive to the inspiratory volume of the breath breaching the first volume threshold, temporarily decreasing the pressure of the pressurized flow of breathable gas from the inspiratory pressure level for expiration by the subject.
Another aspect of the disclosure relates to a system for controlling respiratory assistance of a subject. In one embodiment, the system comprises a pressure generator and one or more processors. The pressure generator is configured to generate a pressurized flow of breathable gas for delivery to the airway of the subject during breaths of the subject, wherein a breath has inspiratory volume during an inspiratory phase and expiratory volume during an expiratory phase. The one or more processors are configured to execute computer program modules including a breathing rate module, an adjustment module, a monitoring module, a comparison module, and a control module. The breathing rate module is configured to determine a breathing rate of the subject. The adjustment module is configured to adjust a first volume threshold based on the determined breathing rate. The monitoring module is configured to monitor inspiratory volumes of individual breaths by the subject. The comparison module is configured to compare the inspiratory volumes of the individual breaths by the subject to the first volume threshold to determine when the inspiratory volumes of the individual breaths have breached the first volume threshold. The control module is configured to control the pressure generator to adjust a pressure level of the pressurized flow of breathable gas, wherein the control module is further configured such that responsive to the inspiratory volume of a given breath breaching the first volume threshold the control module controls the pressure generator to temporarily decrease the pressure level of the pressurized flow of breathable gas for expiration by the subject.
Yet another aspect of the invention relates to a system configured to control volume based respiratory assistance of a subject. In one embodiment, the system comprises means for generating a pressurized flow of breathable gas for delivery to the airway of a subject at an inspiratory pressure level during a breath by the subject, wherein the breath has inspiratory volume during an inspiratory phase and expiratory volume during an expiratory phase; means for determining a breathing rate of the subject; means for adjusting a first volume threshold based on the determined breathing rate; means for monitoring the inspiratory volume of the breath by the subject; means for comparing the inspiratory volume to the first volume threshold to determine when the inspiratory volume of the breath breaches the first volume threshold; and means for temporarily decreasing the pressure level of the pressurized flow of breathable gas from the inspiratory pressure level for expiration by the subject, responsive to the inspiratory volume of the breath breaching the first volume threshold.
These and other objects, features, and characteristics of the present disclosure, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. In one embodiment, the structural components illustrated herein are drawn to scale. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not a limitation. In addition, it should be appreciated that structural features shown or described in any one embodiment herein can be used in other embodiments as well. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of limits. As used in the specification and in the claims, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.